Spark-igniting plug.



No. 820,797. V]`. ATE1\ITB1JVMAY 15, 1906.

R.B.KU HN. SPARK IGNITING PLUG.

APPLICATION FILED MAYlO, 1905.

INVENTOR Y BY QAvY/L2M` ATTORNEY sin ' raient l No. scope?.

To all whom it may concern:

,it known that i, Bonner B. KUHN, of

'I the city of Canton, county of Stark, and

' tion under varying de lees of temperature.'

State of Ohio, have invented@u new and use.

v orwed e-actin contact between the insidia@ vtion-tu e and oth the stem and case and that all the parts lcan be 'drawn and heid tightly together without danger ofbreaking by reason of excessive or uneven compression or of their unequal expansion and contrac- This object is attaine by the construction and arrangement illustrated in the accompanying drawings, in which-Q Figure 1 is a sectional view of an explosiveengine cylinder, showing the igniting-plug appliedtheretc; Fig.' 2, a longitudinal section of the lug; Fig. 3, a detached perspective view o the case and the stern with the insulating-tube thereon in proper relation for assembiing and Fig. 4, a detached View ci the spiral spring, the' set-nut, and the bindingnut in roper relation for assembling.

Simi ar numerals refer to siiniar parte throughout the drawings.

The case l is tubular in general 'forni and is detachably secured, preferabiy byv screwing,

into the a erture 2 in the head 3 of the engine-cylin er 4. The throughbavityof the case is provided with the endwise-tapered section 6, having the reduced end directed outward, and the section 7 ci thecase-cavity y i is preferably slightly'larger than the enlarged.

.- itered from the inner end into the cavity cfend ofthe tapered section. l e

rlhe insulation-tube 8 is adapted to be en the case and is dprovided externaily with the endwise-tapere section 9, which is adapted to neatly fit and bear against the tapered section of the cavity. The inner end section i0 of the y insulation-tube is preferably made slightly less in diameter than the adjacentwali of the cavity of the case, `thus forming the constricted, but continuous, annuiar interval 11 between the insulation-tube and the case at the mouth thereof. The section i2 of the D insulation-tube between the tapered and inner end sections is preferably reduced in di- Specication of Letters Patent. application Anti nay 10, 1905. serial No. 259,726.

atented l5, i966.,

arneter to form the considerably annular cavity 13 within the case, and the cavity oi the case is preferablyreamedout to forno. the annular groove le atr the inner end oi the ta pered section, so as to extend the considerable cavity squarely to this point.

The stein l5 is adapted to be entered from. the inner end into the through axial aperture i6 of the insulation-tube and is provided with the head 17, having its side 18 ccncaved to neatly iit and bear against the tapered or cone-sha ed inner end i9 of the insulation tribe. he head 17 of the stem constitutes one of the electrodes ci. the plug, andthe other electrode is preferably composed ci the end of the wire 20, attached to the case andN terminating ata point adjacent to the eternhead.

The .insulation-collar 2i surrounds the pro jecting outer end 22 of the insuiation--tnbe and bears against the outer end of the case. Theset-nut 23 is adjustabiy secured, preierabi'Y by screwing, on the shanliZ of the stein, an the intervening spring 25, which may be a coil-spring, as shown, is provided and adapt ed to bear against the outer end of the insulation-collar and the inner side of the set-nut, and the thimble or sleeve 26 may be provided on the inner side ci the nut, which is adapted to enter into the cavity of the spring and heid the saine in proper lateral position. By this construction and arran lement ail` the parte of the plug can be tightlgy drawn together by applying the set-nut on the stein and screwing it to compress the spring to the desired pressure. in so doing the tapered or wedgeacting contact ci the insulating-tribe with both the case and the stein-heed brings these parts more tightly together th conid be done with a squareshouldered Contact, and the resiliency of the spring permits 'a greater pressure to be apph'ed to the parts Without danger of 'their being broken by van unequal expansion or contraction oi the parts.

What i claim my invention, and desire to secure by Letters Qatent, is-

l. A n ignitingi-ping comprising case an electrode on its'inner end and having a cavity with an outwardly-i-ednced tapered section therein, an insuiation-tube in the cavity with a cone-shaped inner end and havin@ a tapered section thereon adapted to iit and. .bear against the tapered cavity-section, .a stem in the tube havingan electrodedieadbn the inne: end with a concave side adapted. to iit and bear against the cone-shaped vtube an electrode on its inner end and having aA cavity With an outwardly-reduced tapered section therein; an insulationtube in the cavitjvr with a cone-'shaped inner end and having a tapered section thereon adapted to it and bear against the tapered cavity-section, a stein in the tube having an electrode-head on the inner end with a concave side adapted to fit and bear against the cone-shaped tube end, an insulation-collar around the outer end of the tube and bearing against the outer end of' the caselv and adjustable securing means on the outer part of the stein adapted to bear lagainst the collar.

3. An igniting-plug comprising a case Wi th an electrode on its inner end and having a cavity With an outwardly-reduced tapered section therein, an insulation-tube in the cavity havin atapered section thereon adapted to fit an bear against the tapered cavitysection, a stein in the tube having an electrode-head bearing against thei nner end of the tube, an insulation-collar around the outer end of the tube and bearing against the outer end of the case, a spring around the outer part of the stein and bearing against the outer` end of the collar, and adjustable securing means on the outer part ofA the stem adapted to bear against the spring.

4. In an igniting-plug, an insulation-tube with a cone-shaped inner end and a stem in the tube having a head on the inner end with a concave Side adapted to fit and bear against the cone-shaped tube end.

In testimony whereof I have signed my naine to this speciiication in the presence of two subscribing Witnesses.

ROBERT B. KUHN.

Witnesses:

EUNroE E. HURFORD, HARRY FREASE. 

